The Lee Auto-Disk Adjustable Powder Charge Bar is adjustable between .28 CC and 1.6 CC allowing the reloader to develop precise charges. Each adjustment line on the thimble is .1CC. This charge bar comes packaged with a volume measuring density chart for all of today's popular powders and detailed setting instructions. This is a disk with a micrometer setting on it to precisely adjust the powder charge. It is always recommended to weigh out charges.